I'm a die hard commuter now riding every day all year and am now up to 8,500 miles a year. I ride a Trek Pilot 5.2 and also take it on annual bike tours, just my wife and I, in Europe and recently Eastern Europe.
I logged 30,000 miles on my bike in the last 4 years without any major problems but am constantly irritated by flats. I average a little less than 2 flats per month mostly due to lot's of glass, thorns, nails, small bits of wire, etc where I ride. Aside from that I love riding which includes to the market, out to dinner, to the tennis courts and everywhere possible. My green goal is zero gallons of gas per mile.